Alternator tester

ABSTRACT

An alternator tester is provided for testing an alternator of a vehicle while the alternator is coupled to the vehicle. A sensor is configured to couple to the vehicle and sense a signal related to operation of the alternator. A memory contains data related to operator instructions for performing an alternator tester of a function of vehicle type. A processor configured to provide an output indication of alternator condition based upon the sensed signal. An extra load or connection can be provided for coupling to the electrical system.

The present application is a Divisional of and claims the benefit ofU.S. patent application Ser. No. 10/864,904, filed Jun. 9, 2004 now U.S.Pat. No. 7,246,015, which claims the benefit of U.S. provisional patentapplication Ser. No. 60/477,082, filed Jun. 9, 2003, Ser. No. 10/864,904which is a Continuation-In-Part of and claims priority of U.S. patentapplication Ser. No. 10/098,741, filed Mar. 14, 2002 now U.S. Pat. No.6,885,195, which is a Continuation-In-Part of U.S. patent applicationSer. No. 09/575,629, filed May 22, 2000 now U.S. Pat. No. 6,445,158,which is a Continuation-In-Part of Ser. No. 09/293,020, filed Apr. 16,1999, now U.S. Pat. No. 6,351,102; which is a Continuation-In-Part ofSer. No. 09/426,302, filed Oct. 25, 1999, now U.S. Pat. No. 6,091,245;which is a Divisional of Ser. No. 08/681,730, filed Jul. 29, 1996, nowU.S. Pat. No. 6,051,976, the content of which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to devices for testing an automotivevehicle. More specifically, the present invention relates to a batterycharging system tester for an automotive vehicle.

Automotive vehicles include a storage battery for operating electronicsin the vehicle and using an electric starter to start the vehicleengine. A battery charging system is coupled to the engine and ispowered by the engine when the vehicle is running. The charging systemis used to charge the storage battery when the vehicle is operating.

Many attempts have been made to test the battery of the vehicle. Onetechnique which has been pioneered by Dr. Keith S. Champlin andMidtronics, Inc. of Burr Ridge, Ill. relates to measuring theconductance of batteries to determine their condition. This techniqueand other inventions are described in a number of United States patents,for example, U.S. Patent Nos. U.S. Pat. No. 3,873,911, issued Mar. 25,1975, to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat.No. 3,909,708, issued Sep. 30, 1975, to Champlin, entitled ELECTRONICBATTERY TESTING DEVICE; U.S. Pat. No. 4,816,768, issued Mar. 28, 1989,to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No.4,825,170, issued Apr. 25, 1989, to Champlin, entitled ELECTRONICBATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING; U.S. Pat. No.4,881,038, issued Nov. 14, 1989, to Champlin, entitled ELECTRONICBATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING TO DETERMINEDYNAMIC CONDUCTANCE; U.S. Pat. No. 4,912,416, issued Mar. 27, 1990, toChamplin, entitled ELECTRONIC BATTERY TESTING DEVICE WITHSTATE-OF-CHARGE COMPENSATION; U.S. Pat. No. 5,140,269, issued Aug. 18,1992, to Champlin, entitled ELECTRONIC TESTER FOR ASSESSING BATTERY/CELLCAPACITY; U.S. Pat. No. 5,343,380, issued Aug. 30, 1994, entitled METHODAND APPARATUS FOR SUPPRESSING TIME-VARYING SIGNALS IN BATTERIESUNDERGOING CHARGING OR DISCHARGING; U.S. Pat. No. 5,572,136, issued Nov.5, 1996, entitled ELECTRONIC BATTERY TESTER DEVICE; U.S. Pat. No.5,574,355, issued Nov. 12, 1996, entitled METHOD AND APPARATUS FORDETECTION AND CONTROL OF THERMAL RUNAWAY IN A BATTERY UNDER CHARGE; U.S.Pat. No. 5,585,416, issued Dec. 10, 1996, entitled APPARATUS AND METHODFOR STEP-CHARGING BATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No.5,585,728, issued Dec. 17, 1996, entitled ELECTRONIC BATTERY TESTER WITHAUTOMATIC COMPENSATION FOR LOW STATE-OF-CHARGE; U.S. Pat. No. 5,589,757,issued Dec. 31, 1996, entitled APPARATUS AND METHOD FOR STEP-CHARGINGBATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No. 5,592,093, issuedJan. 7, 1997, entitled ELECTRONIC BATTERY TESTING DEVICE LOOSE TERMINALCONNECTION DETECTION VIA A COMPARISON CIRCUIT; U.S. Pat. No. 5,598,098,issued Jan. 28, 1997, entitled ELECTRONIC BATTERY TESTER WITH VERY HIGHNOISE IMMUNITY; U.S. Pat. No. 5,656,920, issued Aug. 12, 1997, entitledMETHOD FOR OPTIMIZING THE CHARGING LEAD-ACID BATTERIES AND ANINTERACTIVE CHARGER; U.S. Pat. No. 5,757,192, issued May 26, 1998,entitled METHOD AND APPARATUS FOR DETECTING A BAD CELL IN A STORAGEBATTERY; U.S. Pat. No. 5,821,756, issued Oct. 13, 1998, entitledELECTRONIC BATTERY TESTER WITH TAILORED COMPENSATION FOR LOW STATE-OFCHARGE; U.S. Pat. No. 5,831,435, issued Nov. 3, 1998, entitled BATTERYTESTER FOR JIS STANDARD; U.S. Pat. No. 5,871,858, issued Feb. 16, 1999,entitled ANTI-THEFT BATTERY; U.S. Pat. No. 5,914,605, issued Jun. 22,1999, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 5,945,829,issued Aug. 31, 1999, entitled MIDPOINT BATTERY MONITORING; U.S. Pat.No. 6,002,238, issued Dec. 14, 1999, entitled METHOD AND APPARATUS FORMEASURING COMPLEX IMPEDANCE OF CELLS AND BATTERIES; U.S. Pat. No.6,037,751, issued Mar. 14, 2000, entitled APPARATUS FOR CHARGINGBATTERIES; U.S. Pat. No. 6,037,777, issued Mar. 14, 2000, entitledMETHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEXIMPEDANCE/ADMITTANCE;. U.S. Pat. No. 6,051,976, issued Apr. 18, 2000,entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No.6,081,098, issued Jun. 27, 2000, entitled METHOD AND APPARATUS FORCHARGING A BATTERY; U.S. Pat. No. 6,091,245, issued Jul. 18, 2000,entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No.6,104,167, issued Aug. 15, 2000, entitled METHOD AND APPARATUS FORCHARGING A BATTERY; U.S. Pat. No. 6,137,269, issued Oct. 24, 2000,entitled METHOD AND APPARATUS FOR ELECTRONICALLY EVALUATING THE INTERNALTEMPERATURE OF AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No.6,163,156, issued Dec. 19, 2000, entitled ELECTRICAL CONNECTION FORELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,172,483, issued Jan. 9, 2001,entitled METHOD AND APPARATUS FOR MEASURING COMPLEX IMPEDANCE OF CELLSAND BATTERIES; U.S. Pat. No. 6,172,505, issued Jan. 9, 2001, entitledELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,222,369, issued Apr. 24,2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIESFROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,225,808, issued May1, 2001, entitled TEST COUNTER FOR ELECTRONIC BATTERY TESTER; U.S. Pat.No. 6,249,124, issued Jun. 19, 2001, entitled ELECTRONIC BATTERY TESTERWITH INTERNAL BATTERY; U.S. Pat. No. 6,259,254, issued Jul. 10, 2001,entitled APPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ONBATTERIES AND FOR RAPIDLY CHARGING BATTERIES; U.S. Pat. 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No. 6,424,158, issued Jul. 23, 2002, entitledAPPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ON BATTERIES ANDFOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,441,585, issued Aug. 17,2002, entitled APPARATUS AND METHOD FOR TESTING RECHARGEABLE ENERGYSTORAGE BATTERIES; U.S. Pat. No. 6,437,957, issued Aug. 20, 2002,entitled SYSTEM AND METHOD FOR PROVIDING SURGE, SHORT, AND REVERSEPOLARITY CONNECTION PROTECTION; U.S. Pat. No. 6,445,158, issued Sep. 3,2002, entitled VEHICLE ELECTRICAL SYSTEM TESTER WITH ENCODED OUTPUT;U.S. Pat. No. 6,456,045, issued Sep. 24, 2002, entitled INTEGRATEDCONDUCTANCE AND LOAD TEST BASED ELECTRONIC BATTERY TESTER; U.S. Pat. No.6,466,025, issued Oct. 15, 2002, entitled ALTERNATOR TESTER; U.S. Pat.No. 6,465,908, issued Oct. 15, 2002, entitled INTELLIGENT POWERMANAGEMENT SYSTEM; U.S. Pat. No. 6,466,026, issued Oct. 15, 2002,entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING AC IMMITTANCE OFCELLS AND BATTERIES; U.S. Pat. No. 6,469,511, issued Nov. 22, 2002,entitled BATTERY CLAMP WITH EMBEDDED ENVIRONMENT SENSOR; U.S. Pat. No.6,497,209, issued Dec. 24, 2002, entitled SYSTEM AND METHOD FORPROTECTING A CRANKING SUBSYSTEM; U.S. Pat. No. 6,507,196, issued Jan.14, 2003; entitled BATTERY HAVING DISCHARGE STATE INDICATION; U.S. Pat.No. 6,534,993, issued Mar. 18, 2003, entitled ELECTRONIC BATTERY TESTER;U.S. Pat. No. 6,544,078, issued Apr. 8, 2003, entitled BATTERY CLAMPWITH INTEGRATED CURRENT SENSOR; U.S. Pat. No. 6,556,019, issued Apr. 29,2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,566,883,issued May 20, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No.6,586,941, issued Jul. 1, 2003, entitled BATTERY TESTER WITH DATABUS;U.S. Pat. No. 6,597,150, issued Jul. 22, 2003, entitled METHOD OFDISTRIBUTING JUMP-START BOOSTER PACKS; U.S. Pat. No. 6,621,272, issuedSep. 16, 2003, entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING ACIMMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,623,314, issued Sep.23, 2003, entitled KELVIN CLAMP FOR ELECTRICALLY COUPLING TO A BATTERYCONTACT; U.S. Pat. No. 6,633,165, issued Oct. 14, 2003, entitledIN-VEHICLE BATTERY MONITOR; U.S. Pat. No. 6,635,974, issued Oct. 21,2003, entitled SELF-LEARNING POWER MANAGEMENT SYSTEM AND METHOD; U.S.Pat. No. 6,707,303, issued Mar. 16, 2004, entitled ELECTRONIC BATTERYTESTER; U.S. Pat. No. 6,737,831, issued May 18, 2004, entitled METHODAND APPARATUS USING A CIRCUIT MODEL TO EVALUATE CELL/BATTERY PARAMETERS;U.S. Ser. No. 09/780,146, filed Feb. 9, 2001, entitled STORAGE BATTERYWITH INTEGRAL BATTERY TESTER; U.S. Ser. No. 09/756,638, filed Jan. 8,2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIESFROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Ser. No. 09/862,783, filed May21, 2001, entitled METHOD AND APPARATUS FOR TESTING CELLS AND BATTERIESEMBEDDED IN SERIES/PARALLEL SYSTEMS; U.S. Ser. No. 09/880,473, filedJun. 13, 2001; entitled BATTERY TEST MODULE; U.S. Pat. No. 6,495,990,issued Dec. 17, 2002, entitled METHOD AND APPARATUS FOR EVALUATINGSTORED CHARGE IN AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Ser. No.60/348,479, filed Oct. 29, 2001, entitled CONCEPT FOR TESTING HIGH POWERVRLA BATTERIES; U.S. Ser. No. 10/046,659, filed Oct. 29, 2001, entitledENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVE VEHICLE; U.S. Ser. No.09/993,468, filed Nov. 14, 2001, entitled KELVIN CONNECTOR FOR A BATTERYPOST; U.S. Ser. No. 10/042,451, filed Jan. 8, 2002, entitled BATTERYCHARGE CONTROL DEVICE; U.S. Ser. No. 10/093,853, filed Mar. 7, 2002,entitled ELECTRONIC BATTERY TESTER WITH NETWORK COMMUNICATION; U.S. Ser.No. 10/098,741, filed Mar. 14, 2002, entitled METHOD AND APPARATUS FORAUDITING A BATTERY TEST; U.S. Ser. No. 10/112,114, filed Mar. 28, 2002,entitled BOOSTER PACK WITH STORAGE CAPACITOR; U.S. Ser. No. 10/109,734,filed Mar. 28, 2002, entitled APPARATUS AND METHOD FOR COUNTERACTINGSELF DISCHARGE IN A STORAGE BATTERY; U.S. Ser. No. 10/112,105, filedMar. 28, 2002, entitled CHARGE CONTROL SYSTEM FOR A VEHICLE BATTERY;U.S. Ser. No. 10/112,998, filed Mar. 29, 2002, entitled BATTERY TESTERWITH BATTERY REPLACEMENT OUTPUT; U.S. Serial No. 10/119,297, filed Apr.9, 2002, entitled METHOD AND APPARATUS FOR TESTING CELLS AND BATTERIESEMBEDDED IN SERIES/PARALLEL SYSTEMS; U.S. Ser. No. 60/387,046, filedJun. 7, 2002, entitled METHOD AND APPARATUS FOR INCREASING THE LIFE OF ASTORAGE BATTERY; U.S. Ser. No. 10/177,635, filed Jun. 21, 2002, entitledBATTERY CHARGER WITH BOOSTER PACK; U.S. Ser. No. 10/200,041, filed Jul.19, 2002, entitled AUTOMOTIVE VEHICLE ELECTRICAL SYSTEM DIAGNOSTICDEVICE; U.S. Ser. No. 10/217,913, filed Aug. 13, 2002, entitled, BATTERYTEST MODULE; U.S. Ser. No. 10/246,439, filed Sep. 18, 2002, entitledBATTERY TESTER UPGRADE USING SOFTWARE KEY; U.S. Ser. No. 10/263,473,filed Oct. 2, 2002, entitled ELECTRONIC BATTERY TESTER WITH RELATIVETEST OUTPUT; U.S. Serial No. 10/271,342, filed Oct. 15, 2002, entitledIN-VEHICLE BATTERY MONITOR; U.S. Ser. No. 10/310,515, filed Dec. 5,2002, entitled BATTERY TEST MODULE; U.S. Ser. No. 10/310,490, filed Dec.5, 2002, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/310,385,filed Dec. 5, 2002, entitled BATTERY TEST MODULE; U.S. Ser. No.60/437,224, filed Dec. 31, 2002, entitled DISCHARGE VOLTAGE PREDICTIONS;U.S. Ser. No. 10/349,053, filed Jan. 22, 2003, entitled APPARATUS ANDMETHOD FOR PROTECTING A BATTERY FROM OVERDISCHARGE; U.S. Ser. No.10/388,855, filed Mar. 14, 2003, entitled ELECTRONIC BATTERY TESTER WITHBATTERY FAILURE TEMPERATURE DETERMINATION; U.S. Ser. No. 10/396,550,filed Mar. 25, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No.60/467,872, filed May 5, 2003, entitled METHOD FOR DETERMINING BATTERYSTATE OF CHARGE; U.S. Ser. No. 60/477,082, filed Jun. 9, 2003, entitledALTERNATOR TESTER; U.S. Ser. No. 10/460,749, filed Jun. 12, 2003,entitled MODULAR BATTERY TESTER FOR SCAN TOOL; U.S. Ser. No. 10/462,323,filed Jun. 16, 2003, entitled ELECTRONIC BATTERY TESTER HAVING A USERINTERFACE TO CONFIGURE A PRINTER; U.S. Ser. No. 10/601,608, filed Jun.23, 2003, entitled CABLE FOR ELECTRONIC BATTERY TESTER; U.S. Ser. No.10/601,432, filed Jun. 23, 2003, entitled BATTERY TESTER CABLE WITHMEMORY; U.S. Ser. No. 60/490,153, filed Jul. 25, 2003, entitled SHUNTCONNECTION TO A PCB FOR AN ENERGY MANAGEMENT SYSTEM EMPLOYED IN ANAUTOMOTIVE VEHICLE; U.S. Ser. No. 10/653,342, filed Sep. 2, 2003,entitled ELECTRONIC BATTERY TESTER CONFIGURED TO PREDICT A LOAD TESTRESULT; U.S. Ser. No. 10/654,098, filed Sep. 3, 2003, entitled BATTERYTEST OUTPUTS ADJUSTED BASED UPON BATTERY TEMPERATURE AND THE STATE OFDISCHARGE OF THE BATTERY; U.S. Serial No. 10/656,526, filed Sep. 5,2003, entitled METHOD AND APPARATUS FOR MEASURING A PARAMETER OF AVEHICLE ELECTRICAL SYSTEM; U.S. Ser. No. 10/656,538, filed Sep. 5, 2003,entitled ALTERNATOR TESTER WITH ENCODED OUTPUT; U.S. Ser. No.10/675,933, filed Sep. 30, 2003, entitled QUERY BASED ELECTRONIC BATTERYTESTER; U.S. Ser. No. 10/678,629, filed Oct. 3, 2003, entitledELECTRONIC BATTERY TESTER/CHARGER WITH INTEGRATED BATTERY CELLTEMPERATURE MEASUREMENT DEVICE; U.S. Ser. No. 10/441,271, filed May 19,2003, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 09/653,963,filed Sep. 1, 2000, entitled SYSTEM AND METHOD FOR CONTROLLING POWERGENERATION AND STORAGE; U.S. Serial No. 09/654,217, filed Sep. 1, 2000,entitled SYSTEM AND METHOD FOR PROVIDING STEP-DOWN POWER CONVERSIONUSING INTELLIGENT SWITCH; U.S. Ser. No. 10/174,110, filed Jun. 18, 2002,entitled DAYTIME RUNNING LIGHT CONTROL USING AN INTELLIGENT POWERMANAGEMENT SYSTEM; U.S. Ser. No. 60/488,775, filed Jul. 21, 2003,entitled ULTRASONICALLY ASSISTED CHARGING; U.S. Ser. No. 10/258,441,filed Apr. 9, 2003, entitled CURRENT MEASURING CIRCUIT SUITED FORBATTERIES; U.S. Ser. No. 10/705,020, filed Nov. 11, 2003, entitledAPPARATUS AND METHOD FOR SIMULATING A BATTERY TESTER WITH A FIXEDRESISTANCE LOAD; U.S. Ser. No. 10/280,186, filed Oct. 25, 2002, entitledBATTERY TESTER CONFIGURED TO RECEIVE A REMOVABLE DIGITAL MODULE; andU.S. Ser. No. 10/681,666, filed Oct. 8, 2003, entitled ELECTRONICBATTERY TESTER WITH PROBE LIGHT; U.S. Ser. No. 10/748,792, filed Dec.30, 2003, entitled APPARATUS AND METHOD FOR PREDICTING THE REMAININGDISCHARGE TIME OF A BATTERY; U.S. Ser. No. 10/767,945, filed Jan. 29,2004, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No. 10/767,945,filed Jan. 29, 2004, entitled ELECTRONIC BATTERY TESTER; U.S. Ser. No.10/783,682, filed Feb. 20, 2004, entitled REPLACEABLE CLAMP FORELECTRONIC BATTERY TESTER; U.S. Ser. No. 60/548,513, filed Feb. 27,2004, entitled WIRELESS BATTERY MONITOR; U.S. Ser. No. 10/791,141, filedMar. 2, 2004, entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST;U.S. Ser. No. 60/557,366, filed Mar. 29, 2004, entitled BATTERYMONITORING SYSTEM WITHOUT CURRENT MEASUREMENT; U.S. Ser. No. 10/823,140,filed Apr. 13, 2004, entitled THEFT PREVENTION DEVICE FOR AUTOMOTIVEVEHICLE SERVICE CENTERS; which are incorporated herein in theirentirety.

With the advent of accurate battery testing, it has become apparent thatin some instances the battery in the vehicle may be good, and a problemrelated to the battery charging system is the cause of the perceivedbattery failure. A vehicle charging system generally includes thebattery, an alternator, a regulator and an alternator drive belt. Inmost modern vehicles, the regulator is built into the alternator housingand is referred to as an internal regulator. The role of the chargingsystem is two fold. First, the alternator provides charging current forthe battery. This charging current ensures that the battery remainscharged while the vehicle is being driven and therefore will havesufficient capacity to subsequently start the engine. Second, thealternator provides an output current for all of the vehicle electricalloads. In general, the alternator output, the battery capacity, thestarter draw and the vehicle electrical load requirements are matched toeach other for optimal performance. In a properly functioning chargingsystem, the alternator will be capable of outputting enough current todrive the vehicle electrical loads while simultaneously charging thebattery. Typically, alternators range in size from 60 to 120 amps.

A number of charging system testers have been used to evaluate theperformance of the vehicle charging system. These testers generally usean inductive “amp clamp.” The amp clamp is placed around a cable or wireand inductively couples to the cable or wire such that the currentpassing through the wire can be measured. This measurement can be madewithout having to disconnect the wire. In such a system, typically theoperator determines the rated size of the alternator. Next, the operatorconnects the amp clamp to the output cable of the alternator and anelectrical load such as a carbon pile load tester, is placed across thebattery. This is a large resistive load capable of receiving severalhundred amps which will force the alternator to provide its maximumoutput. The maximum output current can then be measured using the ampclamp connection. If the measured output is less than the rated output,the alternator is determined to be malfunctioning. Such a test iscumbersome as the equipment is large and difficult to handle. Further,it is difficult, particularly with compact engines, to reach thealternator output cable. Further, in some cases, the amp clamp may notfit around the output cable. It is also very easy to place the amp clamparound the wrong cable causing a false test.

Another testing technique is described in U.S. Pat. No. 4,207,611, whichissued Jun. 10, 1980 and is entitled APPARATUS AND METHOD FOR CALIBRATEDTESTING OF A VEHICLE ELECTRICAL SYSTEM. The device described in thisreference monitors voltage changes present at the cigarette lighter ofan automotive vehicle in order to determine the condition of thealternator by applying internal loads such as head lamps and blowers,while the engine is running.

SUMMARY OF THE INVENTION

An alternator tester is provided for testing an alternator of a vehiclewhile the alternator is coupled to the vehicle. A sensor is configuredto couple to the vehicle and sense a signal related to operation of thealternator. A memory contains data related to operator instructions forperforming an alternator tester of a function of vehicle type. Aprocessor configured to provide an output indication of alternatorcondition based upon the sensed signal. An extra load or connection canbe provided for coupling to the electrical system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of an automotive battery chargingsystem tester in accordance with the present invention.

FIG. 2 is a simplified flow chart showing steps in a battery test.

FIG. 3 is a simplified flow chart showing steps in a starter test.

FIG. 4 is a simplified flow chart showing steps in a charging systemtest.

FIG. 5 is a simplified flow chart showing further steps in the chargingsystem test of FIG. 4.

FIG. 6 is a simplified flow chart showing steps in a diesel enginecharging system test.

FIG. 7 is a simplified flow chart showing steps to remove surfacecharge.

FIG. 8 is a simplified flow chart showing a ripple test.

FIG. 9 is a simplified block diagram showing generation of an audit codein accordance with one aspect of the invention.

FIG. 10 is a block diagram showing another example embodiment of thepresent invention.

FIG. 11 is a more detailed block diagram related to the implementationof the circuitry shown in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a simplified block diagram of a battery charging system tester10 in accordance with one embodiment of the present invention coupled toa vehicle 12. Vehicle 12 includes a battery 14 having positive andnegative terminals, an alternator with internal regulator 16, variousvehicle loads 18, and a starter motor 20. In operation, battery 14provides power to starter 20 and vehicle loads 18 when the engine invehicle 12 is not running. When the engine in vehicle 12 is running,alternator 16 is used to power vehicle loads 18 and provide a chargingcurrent to battery 14 to maintain the charge of battery 14.

Charging system tester 10 includes a microprocessor 30 which controlsoperation of tester 10 and provides instructions and test resultinformation to an operator through, for example, a display 32. Tester 10includes a battery testing section 34 which is illustrated generally asconductance amplifier 36. Section 34 operates in accordance with, forexample, the conductance based battery testing techniques described inChamplin patents U.S. Pat. No. 3,873,911, issued Mar. 25, 1975, toChamplin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No.3,909,708, issued Sep. 30, 1975, to Champlin, entitled ELECTRONICBATTERY TESTING DEVICE; U.S. Pat. No. 4,816,768, issued Mar. 28, 1989,to Champlin, entitled ELECTRONIC BATTERY TESTING DEVICE; U.S. Pat. No.4,825,170, issued Apr. 25, 1989, to Champlin, entitled ELECTRONICBATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING; U.S. Pat. No.4,881,038, issued Nov. 14, 1989, to Champlin, entitled ELECTRONICBATTERY TESTING DEVICE WITH AUTOMATIC VOLTAGE SCALING TO DETERMINEDYNAMIC CONDUCTANCE; U.S. Pat. No. 4,912,416, issued Mar. 27, 1990, toChamplin, entitled ELECTRONIC BATTERY TESTING DEVICE WITHSTATE-OF-CHARGE COMPENSATION; U.S. Pat. No. 5,140,269, issued Aug. 18,1992, to Champlin, entitled ELECTRONIC TESTER FOR ASSESSING BATTERY/CELLCAPACITY; U.S. Pat. No. 5,343,380, issued Aug. 30, 1994, entitled METHODAND APPARATUS FOR SUPPRESSING TIME-VARYING SIGNALS IN BATTERIESUNDERGOING CHARGING OR DISCHARGING; U.S. Pat. No. 5,572,136, issued Nov.5, 1996, entitled ELECTRONIC BATTERY TESTER DEVICE; U.S. Pat. No.5,574,355, issued Nov. 12, 1996, entitled METHOD AND APPARATUS FORDETECTION AND CONTROL OF THERMAL RUNAWAY IN A BATTERY UNDER CHARGE; U.S.Pat. No. 5,585,416, issued Dec. 10, 1996, entitled APPARATUS AND METHODFOR STEP-CHARGING BATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No.5,585,728, issued Dec. 17, 1996, entitled ELECTRONIC BATTERY TESTER WITHAUTOMATIC COMPENSATION FOR LOW STATE-OF-CHARGE; U.S. Pat. No. 5,589,757,issued Dec. 31, 1996, entitled APPARATUS AND METHOD FOR STEP-CHARGINGBATTERIES TO OPTIMIZE CHARGE ACCEPTANCE; U.S. Pat. No. 5,592,093, issuedJan. 7, 1997, entitled ELECTRONIC BATTERY TESTING DEVICE LOOSE TERMINALCONNECTION DETECTION VIA A COMPARISON CIRCUIT; U.S. Pat. No. 5,598,098,issued Jan. 28, 1997, entitled ELECTRONIC BATTERY TESTER WITH VERY HIGHNOISE IMMUNITY; U.S. Pat. No. 5,656,920, issued Aug. 12, 1997, entitledMETHOD FOR OPTIMIZING THE CHARGING LEAD-ACID BATTERIES AND ANINTERACTIVE CHARGER; U.S. Pat. No. 5,757,192, issued May 26, 1998,entitled METHOD AND APPARATUS FOR DETECTING A BAD CELL IN A STORAGEBATTERY; U.S. Pat. No. 5,821,756, issued Oct. 13, 1998, entitledELECTRONIC BATTERY TESTER WITH TAILORED COMPENSATION FOR LOW STATE-OFCHARGE; U.S. Pat. No. 5,831,435, issued Nov. 3, 1998, entitled BATTERYTESTER FOR JIS STANDARD; U.S. Pat. No. 5,871,858, issued Feb. 16, 1999,entitled ANTI-THEFT BATTERY; U.S. Pat. No. 5,914,605, issued Jun. 22,1999, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 5,945,829,issued Aug. 31, 1999, entitled MIDPOINT BATTERY MONITORING; U.S. Pat.No. 6,002,238, issued Dec. 14, 1999, entitled METHOD AND APPARATUS FORMEASURING COMPLEX IMPEDANCE OF CELLS AND BATTERIES; U.S. Pat. No.6,037,751, issued Mar. 14, 2000, entitled APPARATUS FOR CHARGINGBATTERIES; U.S. Pat. No. 6,037,777, issued Mar. 14, 2000, entitledMETHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIES FROM COMPLEXIMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,051,976, issued Apr. 18, 2000,entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No.6,081,098, issued Jun. 27, 2000, entitled METHOD AND APPARATUS FORCHARGING A BATTERY; U.S. Pat. No. 6,091,245, issued Jul. 18, 2000,entitled METHOD AND APPARATUS FOR AUDITING A BATTERY TEST; U.S. Pat. No.6,104,167, issued Aug. 15, 2000, entitled METHOD AND APPARATUS FORCHARGING A BATTERY; U.S. Pat. No. 6,137,269, issued Oct. 24, 2000,entitled METHOD AND APPARATUS FOR ELECTRONICALLY EVALUATING THE INTERNALTEMPERATURE OF AN ELECTROCHEMICAL CELL OR BATTERY; U.S. Pat. No.6,163,156, issued Dec. 19, 2000, entitled ELECTRICAL CONNECTION FORELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,172,483, issued Jan. 9, 2001,entitled METHOD AND APPARATUS FOR MEASURING COMPLEX IMPEDANCE OF CELLSAND BATTERIES; U.S. Pat. No. 6,172,505, issued Jan. 9, 2001, entitledELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,222,369, issued Apr. 24,2001, entitled METHOD AND APPARATUS FOR DETERMINING BATTERY PROPERTIESFROM COMPLEX IMPEDANCE/ADMITTANCE; U.S. Pat. No. 6,225,808, issued May1, 2001, entitled TEST COUNTER FOR ELECTRONIC BATTERY TESTER; U.S. Pat.No. 6,249,124, issued Jun. 19, 2001, entitled ELECTRONIC BATTERY TESTERWITH INTERNAL BATTERY; U.S. Pat. No. 6,259,254, issued Jul. 10, 2001,entitled APPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ONBATTERIES AND FOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,262,563,issued Jul. 17, 2001, entitled METHOD AND APPARATUS FOR MEASURINGCOMPLEX ADMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,294,896,issued Sep. 25, 2001; entitled METHOD AND APPARATUS FOR MEASURINGCOMPLEX SELF-IMMITANCE OF A GENERAL ELECTRICAL ELEMENT; U.S. Pat. No.6,294,897, issued Sep. 25, 2001, entitled METHOD AND APPARATUS FORELECTRONICALLY EVALUATING THE INTERNAL TEMPERATURE OF AN ELECTROCHEMICALCELL OR BATTERY; U.S. Pat. No. 6,304,087, issued Oct. 16, 2001, entitledAPPARATUS FOR CALIBRATING ELECTRONIC BATTERY TESTER; U.S. Pat. No.6,310,481, issued Oct. 30, 2001, entitled ELECTRONIC BATTERY TESTER;U.S. Pat. No. 6,313,607, issued Nov. 6, 2001, entitled METHOD ANDAPPARATUS FOR EVALUATING STORED CHARGE IN AN ELECTROCHEMICAL CELL ORBATTERY; U.S. Pat. No. 6,313,608, issued Nov. 6, 2001, entitled METHODAND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,316,914, issuedNov. 13, 2001, entitled TESTING PARALLEL STRINGS OF STORAGE BATTERIES;U.S. Pat. No. 6,323,650, issued Nov. 27, 2001, entitled ELECTRONICBATTERY TESTER; U.S. Pat. No. 6,329,793, issued Dec. 11, 2001, entitledMETHOD AND APPARATUS FOR CHARGING A BATTERY; U.S. Pat. No. 6,331,762,issued Dec. 18, 2001, entitled ENERGY MANAGEMENT SYSTEM FOR AUTOMOTIVEVEHICLE; U.S. Pat. No. 6,332,113, issued Dec. 18, 2001, entitledELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,351,102, issued Feb. 26,2002, entitled AUTOMOTIVE BATTERY CHARGING SYSTEM TESTER; U.S. Pat. No.6,359,441, issued Mar. 19, 2002, entitled ELECTRONIC BATTERY TESTER;U.S. Pat. No. 6,363,303, issued Mar. 26, 2002, entitled ALTERNATORDIAGNOSTIC SYSTEM; U.S. Pat. No. 6,377,031, issued Apr. 23, 2002,entitled INTELLIGENT SWITCH FOR POWER MANAGEMENT; U.S. Pat. No.6,392,414, issued May 21, 2002, entitled ELECTRONIC BATTERY TESTER; U.S.Pat. No. 6,417,669, issued Jul. 9, 2002, entitled SUPPRESSINGINTERFERENCE IN AC MEASUREMENTS OF CELLS, BATTERIES AND OTHER ELECTRICALELEMENTS; U.S. Pat. No. 6,424,158, issued Jul. 23, 2002, entitledAPPARATUS AND METHOD FOR CARRYING OUT DIAGNOSTIC TESTS ON BATTERIES ANDFOR RAPIDLY CHARGING BATTERIES; U.S. Pat. No. 6,441,585, issued Aug. 17,2002, entitled APPARATUS AND METHOD FOR TESTING RECHARGEABLE ENERGYSTORAGE BATTERIES; U.S. Pat. No. 6,437,957, issued Aug. 20, 2002,entitled SYSTEM AND METHOD FOR PROVIDING SURGE, SHORT, AND REVERSEPOLARITY CONNECTION PROTECTION; U.S. Pat. No. 6,445,158, issued Sep. 3,2002, entitled VEHICLE ELECTRICAL SYSTEM TESTER WITH ENCODED OUTPUT;U.S. Pat. No. 6,456,045, issued Sep. 24, 2002, entitled INTEGRATEDCONDUCTANCE AND LOAD TEST BASED ELECTRONIC BATTERY TESTER; U.S. Pat. No.6,466,025, issued Oct. 15, 2002, entitled ALTERNATOR TESTER; U.S. Pat.No. 6,465,908, issued Oct. 15, 2002, entitled INTELLIGENT POWERMANAGEMENT SYSTEM; U.S. Pat. No. 6,466,026, issued Oct. 15, 2002,entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING AC IMMITTANCE OFCELLS AND BATTERIES; U.S. Pat. No. 6,469,511, issued Nov. 22, 2002,entitled BATTERY CLAMP WITH EMBEDDED ENVIRONMENT SENSOR; U.S. Pat. No.6,497,209, issued Dec. 24, 2002, entitled SYSTEM AND METHOD FORPROTECTING A CRANKING SUBSYSTEM; U.S. Pat. No. 6,507,196, issued Jan.14, 2003; entitled BATTERY HAVING DISCHARGE STATE INDICATION; U.S. Pat.No. 6,534,993, issued Mar. 18, 2003, entitled ELECTRONIC BATTERY TESTER;U.S. Pat. No. 6,544,078, issued Apr. 8, 2003, entitled BATTERY CLAMPWITH INTEGRATED CURRENT SENSOR; U.S. Pat. No. 6,556,019, issued Apr. 29,2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No. 6,566,883,issued May 20, 2003, entitled ELECTRONIC BATTERY TESTER; U.S. Pat. No.6,586,941, issued Jul. 1, 2003, entitled BATTERY TESTER WITH DATABUS;U.S. Pat. No. 6,597,150, issued Jul. 22, 2003, entitled METHOD OFDISTRIBUTING JUMP-START BOOSTER PACKS; U.S. Pat. No. 6,621,272, issuedSep. 16, 2003, entitled PROGRAMMABLE CURRENT EXCITER FOR MEASURING ACIMMITTANCE OF CELLS AND BATTERIES; U.S. Pat. No. 6,623,314, issued Sep.23, 2003, entitled KELVIN CLAMP FOR ELECTRICALLY COUPLING TO A BATTERYCONTACT; U.S. Pat. No. 6,633,165, issued Oct. 14, 2003, entitledIN-VEHICLE BATTERY MONITOR; U.S. Pat. No. 6,635,974, issued Oct. 21,2003, entitled SELF-LEARNING POWER MANAGEMENT SYSTEM AND METHOD; U.S.Pat. No. 6,707,303, issued Mar. 16, 2004, entitled ELECTRONIC BATTERYTESTER; U.S. Pat. No. 6,737,831, issued May 18, 2004, entitled METHODAND APPARATUS USING A CIRCUIT MODEL TO EVALUATE CELL/BATTERY PARAMETERS.Section 34 is illustrated in very simplified form and conductanceamplifier 36 provides an output to an analog to digital converter 38which is related to the internal conductance of battery 14.

A DC voltage sensor 40 includes voltage scaling resistors 42 and 44 andis coupled to battery 14 to provide an output to analog to digitalconverter 38 which is representative of the DC voltage across battery14. Further, an AC ripple detector amplifier 46 is coupled to battery 14through capacitors 48 and 50 and provides an output to analog to digitalconverter 38 which is representative of the AC ripple voltage acrossbattery 14.

Microprocessor 30 controls analog to digital converter 38 to selectwhich of the three inputs to digitize. Microprocessor 30 includesfirmware, memory, and a software program in accordance with theinvention. The user input 54 is coupled to microprocessor 30 to providethe information to microprocessor 30 from an operator.

Preferably, tester 10 is portable such that it may be easily movedbetween vehicles or otherwise transported. Portability of tester 10 isachieved because tester 10 does not require large internal carbon pileloads to load the battery charging system. Instead, as described herein,tester 10 utilizes loads internal to the vehicle 12 in testing thecharging system. Further, the battery tester performed by tester 10 isin accordance with the non-load battery testing technique as describedabove.

FIGS. 2-8 are simplified block diagrams illustrating steps in accordancewith the invention. User input for the steps can be through user inputdevice 54 and a display can be provided through display device 32. InFIG. 2, block diagram 100 begins at start block 102. At block 104 thetype of vehicle test is selected. If it is an in-vehicle test, controlis passed to block 106. If it is an out of vehicle test, control ispassed to block 120. At block 106, the user is prompted to input thebattery rating standard to be used for the test. Various standardsinclude SAE, DIN, IEC, EN, JIS or a battery stock number. At block 108,the user is prompted to input the battery rating according to theselected standard. A battery test is then performed at block 110, theresults of the battery test are displayed including battery voltage,battery cold cranking amps, and a general condition of the battery suchas good, good but recharged, charged and retest, replace battery or badcell-replace. Any type of battery test may be used, however,conductance, resistance, impedance or admittance based testing asdescribed in the Champlin and Midtronics patents is preferred.

FIG. 3 is a simplified block diagram 118 for an in-vehicle test. Whenthe user initiates a starter test, for example through an input throughuser input 54, control is passed to block 124 and the operator isinstructed to start the engine. Microprocessor 30 detects that theengine is being started by monitoring the resultant in drop in voltageacross battery 14. The starting voltage is measured at block 126. Oncethe engine starts, and the voltage begins to rise, the tester 10 willdisplay one of four different test results. At block 128, if thestarting voltage is low and the battery is discharged, the message“charge battery” is displayed at block 130. At block 132, if thestarting voltage is low and the battery has a full charge, the message“cranking voltage low” is displayed at block 134 along with the measuredvoltage. If at block 136, the starting voltage is normal and the batteryhas a full charge, block 138 displays cranking voltage normal along withthe measured voltage. If, at block 140, the battery test result waseither replaced or bad cell, block 142 displays the message replacebattery. The low and normal cranking voltages can be selected as desiredand using known techniques.

FIG. 4 is a block diagram 150 which illustrates steps in a chargingsystem test in accordance with another aspect of the invention. At block152, the procedure is initiated by the operator while the engine invehicle 12 is running. At block 154, the voltage across battery 14 dueto alternator 16 is measured and displayed. The operator may press andenter button on user input 54 to continue operation and at block 156 theoperator is instructed to turn off all vehicle loads and rev the enginefor 5 seconds. At block 158, the revving of the engine is detected bymonitoring the AC ripple across battery 14 using ripple detectionamplifier 46. If, after 30 seconds, microprocessor 30 does not detectengine revving, control is returned to block 156 and the procedure isrepeated. At block 160, the engine revved voltage is measured andcontrol is passed to block 162 where the operator is instructed to turnloads within the vehicle (i.e., headlights, fans, etc.) on and idle theengine. Again, an enter key on user input 54 is pressed and control ispassed to block 164 and tester 10 measures the load on, engine idlevoltage. At 166, the user is instructed to rev the engine with the loadson and another voltage is obtained at block 168. Control is then passedto block 170 in FIG. 5 and it is determined whether the engine speed hasincreased. At block 172, if there is no charging voltage, that is i.e.,the charging voltage is less than or the same as the idle voltage, anoutput is displayed. Similarly, if the charging voltage is low such thatthe total voltage across the battery is less than, for example, 13volts, an output is displayed. At block 176, if a high charging voltageis detected, such as more than 2.5 volts above the idle voltage, anoutput is displayed. When control reaches block 178, an output isprovided indicative of the diode ripple voltage. This voltage can beobtained during any of the measurements where the engine is revved. Ifthe ripple voltage is greater than, for example, 130 mV, an indicationis provided that there is a diode or a stator problem.

FIG. 6 is a block diagram of a diesel test algorithm 250. If the tester10 does not detect a charging or a ripple voltage, the tester begins thediesel test algorithm shown at 250. This allows the glow plugs of adiesel engine to turn off. If, at any time during the procedure, acharging voltage and a ripple are detected, the normal test procedurewill resume. At block 252, the user is asked to input information as towhether the engine under test is a diesel engine. If the engine is not adiesel engine, a charging system problem is indicated. If the engine isdiesel, control is passed to block 254 and a post heating delay, such as40 seconds, passes at block 256, if there is a post heating or glowplugs off condition, then a charging system problem is indicated. Ifthere is a post heating or glow plug on condition, the operator isinstructed to warm up the plugs and retest, or check the glow plugs.

Additionally, the tester 10 can receive a temperature input from theoperator and adjust the battery test appropriately.

If the battery test indicates that the battery may have been chargedbefore testing, the user is prompted to indicate whether the test isbeing performed before charging the battery or after charging thebattery and the system is retested.

If the tester 10 determines that the battery may have surface charge,the operator is instructed to turn on the vehicle head lights asindicated in flow chart 300 at block 302. If a drop in voltage isdetected at block 304 indicating that the head lights have been turnedon, control is passed to block 306. If, however, the head lights havenot been turned on, control is returned to block 302. At block 306, thesystem is retested. Flow chart 320 of FIG. 8 shows a noise detectionalgorithm. If excessive ripple is detected during engine idle periods atblock 322, the operator is instructed to check system loads at block324. At block 326, the system is retested.

Based upon the test, an output can be printed or otherwise provided toan operator indicating the results of the battery test, the batteryrating, the actual measured battery capacity, the voltage, the voltageduring cranking and whether the cranking voltage is normal, thecondition of the charging system along with the idle voltage and theload voltage and the presence of excessive diode ripple.

In general, the present invention provides the integration of analternator test with a battery test, an alternator test with a startertest, a starter test with an battery test, or an alternator test with abattery test and with a starter test. The invention allows informationfrom any of these tests to be shared with the other test(s).

In one aspect, tester 10 measures the voltage across battery 20. Boththe AC and DC voltages are recorded. The AC voltage is used to identifyalternator diode and stator faults. The DC voltage measurement is usedto determine if the charging system is functioning properly. Theelectrical loads of the vehicle are used to load the alternator forconvenience. However, other types of loads can also be applied. Thetester continually monitors the charging voltage across the battery. Theoperator is instructed to turn on vehicle loads and rev the engine. Thecharging voltage is recorded with the engine revved. In a properlyfunctioning charging system, this charging voltage should be greaterthan the measured battery voltage with the engine off. This indicatesthat current is flowing into the battery and thus the battery is beingcharged even with loads applied to the charging system. This testingprinciple does not require knowledge of the alternator size, or even theamount of current that the alternator is producing. In the testing,various DC voltages across the battery are measured including batteryvoltage with the engine off (stead state voltage), battery voltage withthe engine running at idle (idle voltage), battery voltage with theengine revved, for example between 1,000 RPM and 2,500 RPM, and thevehicle loads off and battery voltage with the engine revved and vehicleloads on. The AC voltage across the battery which is measured with theengine running is used to detect excessive ripple which may be caused bya faulty diode or stator. Ripple of over about 130 mV is indicative of adiode or stator problem. Additionally, the ripple can be used by tester10 to detect changes in engine RPM.

An initial revving of the engine can be used prior to returning to idleto ensure that the alternator field circuit is excited and conductingcurrent. If the idle voltage with the loads off is less than or equal tothe steady state voltage, then a charging problem exists. If thecharging voltage exceeds the steady state voltage by more than, forexample, 0.5 volts, then a regulator problem is indicated.

With the engine revved and the vehicle loads (such as head lights,blower, rear defrost, etc.) turned on, the revved and loaded voltageacross the battery is recorded and compared to the steady state batteryvoltage. If the charging voltage with loads turned on while the engineis revved is not greater than the steady state voltage, then current isnot flowing into the battery and the battery is not being charge. Thisindicates a problem and that the alternator cannot meet the needs of thevehicle while still charging the battery.

With the present invention, the battery test can be used to preventincorrectly identifying the charging system as being faulty. Thus, thebattery test ensures that a good battery is being charged during thecharging system test. The measurement of the cranking voltage while theengine is being started is used to determine whether there is a starterproblem. In diesel engine applications, the charging system voltage ismeasured to determine if the engine glow plug operation is effecting thecharging system test result. A long cabling (i.e., 10 to 15 feet) can beused such that the tester 10 can be operated while sitting in thevehicle. The battery testing is preferably performed by measuring theconductance, impedance, resistance or admittance of the battery.Further, the battery test with the engine off can be compared with thebattery test with the engine on and used to diagnosis the system.

Another aspect of the present invention relates to the generation of an“audit code” based upon the results of a test. As used herein, the termaudit code refers to an encrypted code which contains information abouta test performed on an electrical system of a vehicle. Such informationcan be particularly useful in monitoring the operation and usage of testequipment. For example, if the present invention is used to testautomobiles and warranty claims are then submitted to a manufacturerbased upon the results of a test, the present invention can output anaudit code after the completion of the test. A manufacturer can decryptthe audit code and reject a warranty claim if the audit code indicatesthe claim has been falsified. The audit code can contain information, inan encrypted format, which relates to the tests which were performed ona particular vehicle. For example, a manufacturer, such as a vehiclemanufacturer, can audit the test(s) performed on a vehicle to reduce theoccurrence of warranty fraud. warranty fraud can occur when anunscrupulous operator attempts to falsify test results in order toreturn a properly functioning component or to receive payment forservices which were not actually performed on a vehicle. Warranty fraudcan cost a manufacturer a great deal of money and also lead tomisdirected research and development efforts in an attempt to correctdefects which do not actually exist. In such an embodiment, any of thetests performed by the present invention or measurements obtained by theinvention can be included in the audit code. More generally, the auditcode of the present invention can be formed using the results of anystarter motor test, alternator test, battery test or a AC ripple test.In a general embodiment of this aspect of the present invention, theparticular testing technique used to obtain the test results may be anyappropriate technique and is not limited to be specific techniques setforth herein.

FIG. 9 is a simplified block diagram 350 showing steps in accordancewith generation of an audit code of the present invention. The steps setforth in block diagram 350 are typically carried out by, for example, amicroprocessor such as microprocessor 30 shown in FIG. 1. However, thesteps may be implemented in hardware, software or their combination asappropriate.

Block 352 illustrates the general step of outputting test results. Thetest results can be, for example, the results of a starter test,alternator test, battery test or diode ripple test. At block 354, themicroprocessor 30 retrieves the data which will be used in the auditcode. As discussed herein, such data can comprise many different typesof data including rating, operator or user identification, test data orresults, etc. For example, this data can be retrieved from memoryassociated with the microprocessor. At block 356, microprocessor 30generates an audit code based upon the retrieved data in accordance withany of the embodiments set forth herein. The audit code is generatedusing an encryption algorithm. The particular algorithm used can beselected in accordance with the desired level of security. However, formost systems, a transposition offset cipher can be used in whichindividual data elements are transposed and offset by known amounts.More complex algorithms such as RSA, rotating codes or public key basedencryption algorithms can be used if desired. At block 358, themicroprocessor 30 outputs the audit code, for example, on display 32. Anoperator can then copy the audit code onto a return form, or enter theaudit code into a database system of the manufacturer. If the audit codewill be handled directly by an operator, the code and encryptionalgorithm should be such that the output is alphanumeric or in a formwhich is otherwise easy to copy onto a warranty submission form. Ofcourse, if the code is electronically submitted, for example through adata link, the code can take any form. Such data links include, forexample, modem or hard wired links, infrared links, ultrasonic links,bar code outputs, RF outputs, or other techniques for conveying datawhich are known in the art.

The particular data which is used to form the audit code can be any ofthe final test results or intermediary measurements (that is,measurements which are used to obtain a final test result) set forthherein. For example, the measured starter voltage during cranking, thestarter test result, the measured alternator voltage or voltages, thealternator test result, or the ripple test result can be encoded.Battery condition, state of charge or time to charge information can beencoded. Further, the date of the test can be maintained bymicroprocessor 30 and can be included in the audit code. Using thisinformation, the test can be audited to determine if the measuredalternator voltage or starter voltage could actually result in theencoded test results. Further, by checking the encoded date, it ispossible to determine whether the vehicle was even in a repair shopduring the test period. The raw data, such as voltage levels or otherintermediary measurements, can be used by a manufacturer to collect dataregarding the operation of a product. For example, a manufacturer couldnote that a particular change to an alternator resulted in astatistically significant drop in alternator voltages as measured inactual vehicles. This could be used in a research and development effortto improve system operation.

Other information which can be encoded into the audit code includesinformation regarding the make or model of the vehicle or battery,information such as the VIN identifying the vehicle, temperatureinformation, time of day information, an identification which specifiesthe operator, the identity of the dealer or shop performing the test,data which identifies the test equipment or the software used in thetest equipment, system or component ratings or other information enteredby an operator, the number or sequence of the test, or otherinformation.

In the past, when an alternator of a vehicle was suspected of beingdefective, the alternator could be tested by removing the alternatorfrom the vehicle and performing what was referred to as a “bench test”on the alternator. In a bench test, the alternator is connected to amotor which is used to turn the alternator. The output from thealternator can then be observed. Further, more complex bench testingtechniques include various test leads which can be coupled to thealternator for more complex testing. For example, some alternatorsinclude an electrical plug that is used by the vehicle computer system,or is employed purely for testing, which provides access and control ofvarious functions of the alternator. The present invention includes aportable alternator tester which allows an operator to perform complextests on an alternator of a vehicle without removing the alternator fromthe vehicle. The testing circuitry is preferably implemented in ahand-held configuration. For example, if the tests discussed aboveindicate that the alternator of the vehicle has failed, additional testscan be performed using this portable in-vehicle alternator tester. Thealternator tester relies on the engine of the vehicle to spin thealternator and does not require connecting the alternator to a alternatepower source.

FIG. 10 is an example embodiment of tester 10 shown coupled toalternator 16 and configured to perform an in-vehicle alternator test.Tester 10 is preferably hand-held and is shown to generally includesensor circuitry 400 for coupling to alternator 16 along with auxiliarysensor or electrical connection 398. A memory 402 is also shown coupledto the microprocessor 30. During operation, the additional sensorconnection 398 can be used to sense a signal related to operation of thealternator 16. The memory 402 contains data related to operatorinstructions for performing an alternator test as a function of vehicletype. During operation, an operator or other input can be used toprovide an input to microprocessor 30 related to the type of vehicle oralternator being tested. Based upon the input data being tested.Typically, each vehicle requires a different testing procedure to testthe vehicle's alternator. Microprocessor 30 recalls the appropriateoperator instructions from memory 402 which are related to the testingprocedures for testing the alternator 16. Steps or instructions areoutput on display 32 to an operator. The output can provide instructionsrelated to the placement of sensor 398, the particular leads orconnections that are required to test the alternator, or particularsteps in operating the vehicle which can be used by microprocessor 30 toperform an alternator test. In some embodiments, the tester includes aplurality of test leads or connectors and operator instructions storedin the memory instruct the operator as to which one, or ones, should beused and/or how they should be connected based upon information inputinto the tester related to the vehicle, alternator, or engine, etc. Insome embodiments, the tester 10 includes a load 410 which can be used bythe microprocessor 30 to selectively apply electrical loads to thealternator 16 for use in performing the alternator test.

FIG. 11 is a simplified block diagram of tester 10 showing a somewhatmore detailed view of the components of tester 10 used in the portablein-vehicle alternator tester of the present invention. Tester 10includes Kelvin connections 420 configured to couple to terminals ofbattery 14. These Kelvin connections are used in accordance with testingtechniques which employ dynamic parameters, such as those discussedabove in the Champlin and Midtronics, Inc. patents. A forcing functionis applied by a forcing function source 422. The forcing function is adynamic signal which is either injected into the battery 14 or drawnfrom the battery 14 which has a time varying component. The conductanceamplifier 36 is configured to measure the voltage across the battery andprovide an output to A/D converter 38 for use by microprocessor 30.Switches 424 are configured to switch out the forcing function force 42and switch in an internal load 410 for coupling to the electrical systemof the vehicle. The load 410 can be optionally controlled bymicroprocessor 30. Further, microprocessor 30 controls operation ofswitches 424. Alternator input/output circuitry 430 is configured toconnect to an access point 432 on alternator 16 through a connector 434.The specific type of access point 432 and connector 434 can vary basedupon the vehicle type, the alternator type, the particular test which isdesired to be performed or other factors. I/O circuitry 430 couples tomicroprocessor 30 and is configured to provide control signals toalternator 16 and/or sense signals generated by alternator 16. In someembodiments, access point 432 is used to connect the alternator 16 tothe computer systems of the vehicle or other circuitry of the vehiclewhich is used to control or sense operation of the alternator 16. Duringan in-vehicle alternator test, this connection between the vehicle andthe alternator 16 can be disconnected so that the connector 434 can beconnected to access point 432 and thereby provide access to thealternator 16 by microprocessor 30. The load 410 can be of a desiredsize, for example the load can configured to draw less than 50 amps. Inorder to reduce the size of the tester 10, additional cooling componentscan be used to prevent the load 410 from overheating. For example, aheat sink, a fan, or other techniques can be used to cool the load 410.The wiring 436 which connects I/O circuitry 430 to connector 434 can besufficiently long to allow an operator to be positioned at a convenientlocation during the alternator testing. For example, the operator can bepositioned within the vehicle to control operation of the vehicle, orcan be at other locations and not require to have direct access to thealternator 16 during the testing procedure.

In another example embodiment, the test circuitry 10 is configured tocouple to a battery tester platform, for example through a databus. Insuch an implementation, the display 32 and input 54 can be implementedin the battery tester platform. Further, the microprocessor 30 mayoptionally be implemented in the battery tester platform. As usedherein, “sensing circuitry” can include, for example, the I/O circuitry430 and/or conductance amplifier 36, analog to digital converter 38 orother circuitry. Further, an auxiliary sensor is provided, for example,by the I/O circuitry 430, amplifier 36 or other circuitry and cancomprise voltage, current, frequency, ripple, phase or other types oftechniques.

During operation, tester 10 is used to perform an in-vehicle alternatortest which allows pin point determination of alternator failure. Forexample, the pin point testing can be initiated by an operator, orautomatically, upon the detection of a problematic alternator using thetechniques discussed above. A particular cable 36 and connector 34 isrequired for a particular vehicle and/or alternator type. For example,the microprocessor 30 can receive an input through input 54 whichprovides information related to the vehicle and/or alternator type orother information. Based upon this information, the microprocessor 30accesses a database contained in memory, for example internal memory ormemory 402 shown in FIG. 10 and retrieves information related to aparticular cable type for testing the selected alternator/vehicle. Theoperator is then instructed, for example using display 32 to select theappropriate cable and plug the cable into connector 438 for coupling toI/O circuitry 430. The operator can be further instructed regarding theproper placement of the cable for the test procedure. For example, theconnector 434 can be connected to access point 432 of alternator 16. Thedisplay 32 can be further used to instruct the operator to start theengine of the vehicle or take other steps for use in the testingsequence. During a testing sequence, depending on the particular type ofaccess point 432, the microprocessor 30 can access the lamp circuit,field terminals, diode trio, “S-terminal”, control electronics, or othercircuitry or electrical connections within alternator 16. Further, insome configurations the microprocessor 30 can control operation of thealternator 16 for example to increase the voltage provided by thealternator 16, and the resultant change in operation of the alternatorcan be monitored for diagnostics purposes. If the test determines thatthe alternator has failed or is in the process of failing, a databasestored in memory can be used to suggest a replacement alternator partnumber. The result of the alternator test can be provided in the form ofan audit code such as that discussed above. The cabling 436 can includean internal voltage regulator to test alternators of the type which useexternal regulators. Further, such circuitry can be implemented in theI/O circuitry 430.

The particular testing procedure set forth with regard to FIG. 10 can beinitiated on its own, or it can be initiated based upon the results ofthe alternator test described above. After performing the alternatortest, the microprocessor 30 can provide an output related to operationof the alternator 16, for example, whether a diode, field, stator, diodetrio or other component has failed. The additional sensor connection canbe used to sense operation of a lamp circuit, a sense circuit, ignitionof the vehicle, the field of the alternator, the stator connector of thealternator, the ground of the alternator or vehicle, the B+ connectionof the alternator, or other aspects of the alternator or electricalsystem. Depending on the type of vehicle or alternator, any number ofconnections can be used. In various aspects, the tester 10 isimplemented in a portable tester. In some embodiments, a battery testcan be included in the testing operation and performed by microprocessor30 using the techniques discussed above. In one embodiment, a smallinternal load is employed which loads the electrical system to less than50 amps of current.

Memory 402 can contain a database of information which is based uponvehicle make, model and year, alternator type, load, or other data, forexample. If an alternator component is indicated as being in failuremode, or approaching failure, the memory can contain information relatedto an appropriate replacement part, for example by manufacturer and partnumber. The replacement parts can be based upon alternator type, vehicletype including model and/or year, engine type, etc. In addition to beingoutput on a display, the results of the test can be provided in the formof an audit or test code as described above. The connection to theelectrical system of the vehicle can be in the form of a universalconnector configured to adapt Kelvin connections to the battery and/oralternator lead adapters. A voltage regulator can be provided to testalternators of the type which include external voltage regulators.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. A method of testing an alternator of a vehicle, the methodcomprising: providing sensing circuitry configured to couple to thealternator while the alternator is coupled to the vehicle; providinginstructions to an operator related to connecting at least one componentof the alternator to the sensing circuitry, sensing a signal related tooperation of the at least one component; and determining a condition ofthe alternator based on the sensed signal.
 2. The method of claim 1wherein the step of connecting comprises connecting an electrical pathof the at least one component to the sensing circuitry.
 3. The method ofclaim 2 wherein the step of connecting further comprises connecting thesensing circuitry and the electrical path of the alternator with anauxiliary sensor connector.
 4. The method of claim 1 and furthercomprising suggesting a replacement part for the at least one componentbased on a vehicle type if the at least one component is approachingfailure or has failed.
 5. The method of claim 1 and further comprisinggenerating an output indicating the condition of the at least onecomponent of the alternator.
 6. The method of claim 1 and furthercomprising determining a condition of a battery coupled to thealternator.
 7. The method of claim 1 and further comprising selecting anelectrical path from a plurality of electrical paths to couple to thesensing circuitry based on a vehicle type.
 8. The method of claim 1 andfurther comprising generating an encrypted code based on the conditionof the at least one component of the alternator.
 9. The method of claim1 wherein providing instructions comprises retrieving instructions froma memory.
 10. The method of claim 1 wherein providing instructionscomprises providing instructions based upon information related tovehicle type.
 11. The method of claim 1 wherein providing instructionscomprises providing instructions based upon information further relatedto vehicle model.
 12. The method of claim 1 wherein providinginstructions is based upon information further related to the vehicleyear.
 13. The method of claim 1 wherein providing instructions is basedupon information related to the engine of the vehicle.
 14. The method ofclaim 1 wherein providing instructions is based upon information relatedto the alternator of the vehicle.
 15. The method of claim 1 whereinproviding instructions is based upon information related to connectingan electrical load to the alternator for use in determining a conditionof the alternator.
 16. An alternator tester for testing an alternator ofa vehicle while the alternator is coupled to the vehicle, comprising: asensor configured to couple to the vehicle and sense a signal related tooperation of the alternator; a memory containing data related tooperator instructions for performing an alternator test as a function ofinformation related to vehicle type; and a processor configured toprovide an output indication of alternator condition based upon thesensed signal.
 17. An alternator tester for testing an alternator of avehicle while the alternator is coupled to the vehicle, comprising: asensor configured to couple to the vehicle and sense a signal related tooperation of the alternator; an additional sensor or electricalconnection; a processor configured to provide an output indication ofalternator condition based upon the sensed signal and the additionalsensor or electrical connection.